PTL 1 describes a stacked solid-state imaging apparatus. The stacked solid-state imaging apparatus described in PTL 1 generates noise when resetting signal charges. Specifically, in the case where a shape of a reset pulse in the off is sharp, to which one of a source and a drain of a reset transistor charges on a channel move is randomly determined. Therefore, this appears as kTC noise. The kTC noise is also generated with capacitance coupling between a reset signal line and a pixel electrode, and the like.
In addition, a stacked solid-state imaging apparatus cannot completely cancel kTC noise even by using correlated double sampling. This is because, in the stacked solid-state imaging apparatus, charges cannot completely be transferred due to a structure in which a photoelectric conversion unit provided above a semiconductor substrate and the semiconductor substrate are connected to each other with a material having high conductivity, such as a metal. After the reset, next signal charges are added with the kTC noise remaining. Therefore, signal charges on which kTC noise is superimposed are read. Accordingly, the solid-state imaging apparatus described in PTL 1 has a problem of an increase in kTC noise.
For reducing kTC noise, a technique described in PTL 2 has been proposed.
FIG. 15 is a diagram illustrating a unit pixel and its peripheral circuit described in PTL 2. In a solid-state imaging apparatus described in PTL 2, a reset of signal charges generated by photodiode 512 are started by fully turning on row selection transistor 518 for unit pixel 510 on the selected row. Here, one terminal of amplifying transistor 514 for all unit pixels 510 on this row is connected to a low-impedance voltage source included in source power supply 530 via column signal line 524. Transistor 520 connected to source line 522 is biased as a current source with a waveform Vbias of gate 526. Amplifying transistor 514 and transistor 520 form an amplifier having a negative gain. A channel resistance of reset transistor 516 is changed by reduction reset power supply 550. Specifically, the channel resistance of reset transistor 516 is gradually increased by an application of a reset pulse, which is generated from reduction reset power supply 550 and has an inclined waveform, to the gate of reset transistor 516. The bandwidth of the kTC noise generated from reset transistor 516 is inversely proportional to the channel resistance of reset transistor 516. Therefore, the more the channel resistance increases, the more the bandwidth of the kTC noise decreases. Accordingly, when the bandwidth of the kTC noise is reduced to a bandwidth of the amplifier composed of amplifying transistor 514 and transistor 520, the kTC noise is suppressed by negative feedback from the amplifier.